Which statement describes an effect of natural
selection on a species?
(1) it favors the survival of certain members
of the species and results in a change in
the proportion of individuals with highly
adaptive traits.
(2) it provides feedback mechanisms for members
of a species and results in a change in the
proportion of individuals with homeostatic
controls.
(3) it leads to reproduction with other species,
increasing the number of different adaptations.
(4) it increases competition between populations
that occupy different niches, increasing the
chance of extinction of the less-adapted
species.

When elements that form a mineral dissolve in hot water, they form a mixture called a(n) a)geode b)vein c)evaporation d)crystallization e)magma f)lava g)solution h)gem

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

Which was most likely an effect on society that resulted from improvements in blood handling during world war i and world war ii?